1. Field of the Invention
The invention relates to a process and a conditioning agent for the treatment of effluent and atmospheric pollutants.
2. Description of Related Art
In the biological treatment of effluent or waste water, micro-organisms convert the organically usable ingredients of the effluent to be purified into cell material or into gases such as, e.g., CO2, methane, hydrogen sulfide and others. Depending on the process management, one differentiates between aerobic or anaerobic processes, wherein in communal effluent purification plants as a rule the aerobic processes are used which are better manageable. In such effluent purification plants a mechanical purification is followed by biological decomposition in an activated sludge tank wherein the carrier of biological purification, i.e., the sludge activated by micro-organisms, is received. Air is introduced into this activated sludge tank to thus supply the oxygen required for biological conversion. In this aeration of the effluent in the activated sludge or aeration tank there form slimy, macroscopically discernible flakes which settle as sedimented sludge when aeration is completed.
In accordance with the publication www.uni-potsdamm.de/u/putz/oktober 1996/30.htm, organic or inorganic polymers which support the growth of flakes are added to the effluent in order to raise the efficiency of the biological conversion. The polymers are designed for the formation of flakes that are as compact and dense as possible and a surface with a low degree of unevenness, which later agglomerate into larger conglomerates of flakes and thus are impervious to the effect of shear forces owing to the flow of effluent.
The like flocculation aids are polymers having a different charge density, charge distribution, and molecular size depending on the purpose to be achieved. They are used for the separation of solids from suspensions with organic or inorganic particles, which may be distributed to a degree of colloidal consistency. Owing to the high adsorption potential, flocculation aide act as a link between the solid particles and microflakes created by the use of flocculating agents, which build up into larger-size flakes (flocculation).
Besides the polymers acting as flocculation aids, the conditioning agent may moreover contain precipitation and flocculating agents. In effluent purification, Al or Fe salts are frequently used as flocculating agents, which form precipitations having a very large surface in particular ranges of pH. On these flakes heavy metals or other undesirable effluent components may be adsorbed. In effluent purification, monomer salts e.g. of aluminum, calcium, iron and magnesium, or polymer aluminum or iron compounds, respectively, are used as precipitating agents.
Despite considerable progress in polymer chemistry, the present conditioning agent may only be designed for an average composition of the effluent to be treated, wherein biological conversion may not suffice requirements particularly in the event of biosphere fluctuations, i.e., fluctuations of the proportion of organic matter in the effluent to be treated.